Magma is molten, liquid rock found under the surface of the Earth. Magma can also contain crystals, rock fragments and dissolved gases. The liquid part of magma is called the melt.

Earth is divided into three areas. The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. Magma originates in the lower part of the Earth’s crust and in the upper portion of the mantle. There, high temperatures and pressure cause some rocks to melt and form magma.

Magma is extremely hot—between 700 and 1,300 degrees Celsius (1,292 and 2,372 degrees Fahrenheit). When magma rises to the surface of the Earth through vents or during volcanic eruptions, it becomes lava. When lava stops flowing and cools, it hardens into igneous rock.

Magma can rise through breaks in the solid rocks of the crust and accumulate in large underground reservoirs called magma chambers. Heat from magma chambers can warm groundwater, which sometimes rises to the surface and forms hot springs.

Magma wells up through cracks in the seafloor and hardens into crust. Islands can be created this way. The Hawaiian Islands in the Pacific Ocean were formed by a series of underwater volcano eruptions whose lava hardened and eventually built up into the island chain.Magma is molten, liquid rock found under the surface of the Earth. Magma can also contain crystals, rock fragments and dissolved gases. The liquid part of magma is called the melt. Earth is divided into three areas. The core is the superheated center, the mantle is the thick, middle layer, and the crust is the top layer on which we live. Magma originates in the lower part of the Earth’s crust and in the upper portion of the mantle. There, high temperatures and pressure cause some rocks to melt and form magma. Magma is extremely hot—between 700 and 1,300 degrees Celsius (1,292 and 2,372 degrees Fahrenheit). When magma rises to the surface of the Earth through vents or during volcanic eruptions, it becomes lava. When lava stops flowing and cools, it hardens into igneous rock. Magma can rise through breaks in the solid rocks of the crust and accumulate in large underground reservoirs called magma chambers. Heat from magma chambers can warm groundwater, which sometimes rises to the surface and forms hot springs. Magma wells up through cracks in the seafloor and hardens into crust. Islands can be created this way. The Hawaiian Islands in the Pacific Ocean were formed by a series of underwater volcano eruptions whose lava hardened and eventually built up into the island chain.